Abstract
Transpapillary intraductal ultrasonography (IDUS) is especially useful for preoperative evaluation of the extent of bile duct cancer and for assessment of small stones in the bile duct. It is usually easy to insert a microscanner (MS) with a guide wire channel into the common bile duct without endoscopic sphincterotomy (EST), and is possible to introduce it into the right and left intrahepatic bile ducts. It is important to well understand the orientation of the bile duct and its surrounding organs, which allows reduction of fluoroscopy and examination time. IDUS should be performed before EST and biliary drainage since these procedures induce an artifact of wall thickening of the bile duct, which interfere with preoperative evaluation of the longitudinal extent of bile duct cancer.
